Method of recording



1966 R. D. ERICIKSON METHOD OF RECORDING Original Filed Aug. 11. 1961FIG.

FIG.3

INVENTOR. ROGER D. ERiCKSON United States Patent 6 Claims. 01. 346-1)This application is, a divisional application of my copendingapplication, Serial No. 130,808, filed on August 11, 1961, and subjectmatter disclosed but not claimed in the present application is disclosedand claimed in said copending application. v

The present invention relates to a method of producing a record in theform of an image or trace which is immediately visible and usable and isaccomplished in full view of the operator thereby providing rapid accessto recorded information.

An object of the invention is to provide an improved method of recordinghaving particular utility in multichannel-oscillography and providingrapid trace appearance, and good contrast and stability.

Oscillographic recorders which produce immediately visible traces ofelectrical phenomena under observation are known in the prior art. Onesuch form of recording oscillograph is described in United StatesLetters Patent No. 2,580,427, granted to C. A. Heiland on January 1,1952. Another form of such a recording oscillograph is disclosed in theapplication for United States patent, filed on September 8, 1958, by R.S. Kampf andbearing Serial No. 759,675, issued as Patent 3,066,299 onNovember 27, 1962. Such oscillographs are used in scientific, military,and medical fields. In many such applications, rapid access to therecorded information is an essential requirement.

A unique aspect of the invention described in Patent 2,580,427 is therealization that the use of a recording radiation beam, principally inthe invisible portion of the spectrum, when matched with a recordingpaper coated with an emulsion primarily responsive to such radiations,permits recording of multiple high, 'as well as low, frequencyphenomena, which recording becomes immediately visible in ordinary roomlight, without the delay encountered in the prior art of so-calledwet-process development.

The use of such recording paper, referred to in the art as print-outrecording paper, gives an immediate image or trace corresponding to thedeflections of the recording beam of radiation when the recording beamand recording paper aremoving comparatively slowly. At higher writingspeeds or higher paper transport speeds, a latent image or trace isrecorded, as in developing-out recording papers requiring wet-processdevelopment. This latent recorded image can be latensified and therebymade to appear, by exposing it to the room light. The time of suchsecondary exposure required to make the traces visible varies inaccordance with the speed of writing and paper transport speeds, butordinarily is no longer than about a minute. The appearance of thelatent image through secondary exposure is known in the art aslatensification.

For many applications, a latensification time delay of one minute,although extremely short when compared to the time required previouslyfor wet-process development, cannot be tolerated if the full potentialof oscillographic recorders of the type disclosed in Patent 2,5 80,- 427and in Patent 3,066,299, aforementioned, is to be realized. Inapplications involving testing and experimenting, for example, theoscillograph is usedfor monitoring purposes. Often, corrective actionmust be taken within a second or two if a significant change occurs inone of the monitored variables. The one-minute latensification timecould not be tolerated under such conditions. Additionally, if therequirements are such that the paper transport speed is at the rate ofseveral feet per second, an awkward paper-handling problem tends toresult if all of the resulting length of paper has to be latensified byexposure to the room lighting for a period of one minute before thetrace becomes visible.

v A specific object of the present invention is to provide animprovementin the latensification process which results in trace appearance atleast ten times faster than with conventional oscillograph arrangements,as described above. With such improved or forced latensification, thepaper will produce a highly visible trace within one second at recordtravel speedsin excess of eight inches per second and at any frequencyresolvable at the speed, or envelope studies if in excess of resolvablefrequency.

Another object of the present invention is to provide such forcedlatensification in a convenient and inexpensive manner without heat,involving radiation to which the recording paper or material isparticularly sensitive. The use of heat to desensitize the paper andpermit forced latensification is known and has certaindisadvantages. Theuse of hot platens or heat sources to heat the paper from 70 C. to 200C. involves an expensive piece of additional equipmentto anoscillographic recorder. Significant amounts of additional electricalpower are required. The oscillograph operator is subject to the hazardof being burned. The large amounts of heat given ofi by a hot platen orheat source can produce very uncomfortable ambient temperatures for theoscillograph operator or may require the use of significant amounts ofadditional air conditioning. The heat radiation involves wavelengths towhich the print-out papers are not sensitive.

In accordance with the present invention, latensification is produced byradiations to which the recording ma terial is particularly sensitive.By first exposing the recording paper or material for a short time to alow intensity state of radiation, it has been found that a highintensity latensifying radiation defining the same wavelengths may beused with aminimum of fogging. If the low intensityexposure is avoidedan excessive fogging or darkening of the background of the paperresults. By way of example and not limitation, radiation between 3000 A.and 4000 A., in the range of wavelengths to which the paper isparticularly sensitive, is effective in desensitizing the backg round ofthe recording paper or ma terial. The exposure of the paper to thisradiation desensitizes the background or areas of the paper on which nolatent images have been recorded. The exposure times required fordesensitization range from a fraction of a second to several secondsdepending on the degree of desensitization desired. Following the lowintensity exposure, the paper can be exposed to high intensity radiationbetween 3000 A. and 4000 A. The high intensity radiation latensifies thelatent image very rapidly and produces a minimum darkening of thebackground because the background has been desensitized. In the priorart, the use only of high intensity radiations between 3000 A. and 4000A. for latensification was not permissible because these radiationswould also produce excessive darkening o-r fogging of the background.

A better understanding of the present invention may be had from thefollowing detailed description when read in connection with theaccompanying drawings in which:

FIG. 1 is a diagramatic or schematic view in vertical cross-section of aform of oscillograph embodying the novel latensifying method of thepresent invention;

FIG. 2 illustrates a modified latensifier arrangement 3 which may beemployed with an oscillograph such as shown in FIG. 1; and

FIG. 3 is a fragmentary view of the front of an oscillograph such asshown in FIG. 1, illustrating another latensifier arrangement which maybe employed in accordance with the present invention.

The oscillographic recorder illustrated in FIGURE 1 includes acompartment containing a supply reel 1 and a take-up reel 2 for the rollof sensitive recording paper or material 3. An electric motor, notshown, actuates these reels and is controlled by a suitable switchlocated "on the front panel 4 of the oscillograph, as described in theaforementioned Kampf Patent 3,066,299. It will be apparent that in somecases the take-up reel 2 may not be necessary or desirable, and in suchcases the take-up reel 2 may be dispensed with and the recording papermay be permitted to spill out over the table or panel on which theoscillograph is mounted and onto the floor.

In a recording-plane region between the reels, the recording paper isexposed to a recording beam 5 of radiation coming from the respectivegalvanometers, only one of which, here designated 6, is illustrated.Galvanometer 6 is shown mounted in a galvanometer magnet bank 611 whichin practice oridinarily contains 12 galvanometers. It will be understoodthatany arbitrary number of such galvanometers may be provided; forexample, there are three magnet banks containing a total of 36galvanometers in one apparatus embodiment of the specific oscillographon which the instant invention is drawn. Each such galvanometer has asmall mirror, not shown, deflectable by the associated galvanometermovement, that will reflect the recording beam of radiation 5 from asource 7 to that portion of the sensitive recording paper 3 that is atthe time at the recording-plane region between 8. The mirror 8 reflectsthe recording beam to a spot intensity control comprised by a filter 9and through the galvanometer lens to the galvanometer mirror of thegalvanometer 6. The galvanometer mirror reflects the radiant energy backthrough the galvanometer lens to a recording mirror 10, and through arecording lens 11 onto the recording paper 3 on the recording plane.

The oscillographic recorder is open at the front 4 thereby permittingdirect access to the recording paper for loading, latensifying, andviewing. At the upper portion of the front 4 of the recorder,immediately adjacent the recording lens 11, is an amber-colored viewingwindow 12 for enabling the operator to observe the highenergy spots madeby the beams of the radiant energy from the galvanometer mirrors duringthe positioning and recording operation. The window 12 protects theoperator aginst direct exposure to the high energy ultraviolet recordingbeam.

In the form of the invention illustrated in FIG. 1, ambient roomlighting and radiation produced by an electric lamp 13 cooperate tolatensify the latent images on the recording paper as the latter istransported downwardly at the front 4 of the oscillograph. Lamp 13 iscontrolled by a starting switch and an on-off switch, neither of whichis shown but which are provided on a panel on the front 4 of theoscillograph.

As noted hereinbefore, at higher frequencies, the recorded trace is notimmediately visible. During recording at such higher frequencies, alatent image is created, which image appears after exposure to radiationin the visible spectrum. The appearance of this latent image throughsecondary exposure has been termed latensification. An important aspectof the present invention involves the discovery that by first exposingthe recording paper for a short time to a low intensity state ofradiation including wavelengths to which the recording paper isparticularly sensitive, high intensity radiation embracing the samewavelengths of radiation may be used to effect rapid latensificationwithout fogging of the recording paper. In effecting rapidlatensification by this improved method, proper placement of thelatensifying lamp 13 is important, as explained hereinafter.

The latensifier lamp 13, as illustrated in FIG. 1, includes twofluorescent tubes, one tube, designated 14, providing so-called coolwhite light and the other tube, designated 15, providing so-called blacklight .or high intensity ultra-violet radiation. Lamp 14 desirably maycomprise a GE. Type CW fluorescent lamp and lamp 15 may comprise a GE.Type BL fluorescent lamp. In an operative embodiment of the inventionlamp 14 comprised a GE. Type F14T8CW and the lamp 15 comprised a GE.Type F14T8BL.

For extremely rapid latensification, it is important for paper speedsfrom 2 to 8 inches per second, that the direct rays of the lamp 13should not strike the recording paper 3 nearer than approximately oneinch below the amber window 12, as seen in FIG. 1. At lower paper speedsthe distance may be less than one inch. In this region approximately oneinch from the amber window, the recording paper should be exposed onlyto ambient or indirect light containing a low intensity of radiations towhich the paper is particularly sensitive. At very high paper transportspeeds, the interval may desirably be increased to about 2 or 3 inches.The so-called black light from lamp 15 should not strike the paper 3until the latter has been exposed to ambient or indirect light, andadditionally, has received the full intensity of the white light fromlamp 14.

With this latensifier arrangement, the ambient light and the cool whitelight from lamp 14 serve to expose the recording paper or material, fora short time, to a low intensity state of radiation. Such exposure hasbeen found to inactivate the original recording sensitivity of therecording paper so as thereafter to permit rapid forced latensificationby high intensity ultra-violet radiation from the black light from lamp15. Thus, a high intensity latensifying radiation defining the samewavelengths to which the recording paper is sensitive for recording thedeflections of the galvanometer beams efiectively may be used forlatensification of the latent recorded images or traces, with a minimumof fogging. The presence of visible light in the wavelength band from5000 A. to 7000 A. in the cool white light is useful for the purpose ofviewing the record.

By way of example and not limitation, one form of recording paper 3which has been found to be particularly useful in the practice of thepresent invention is that described in US. patent appliation Serial No.93,289 filed by Troy A. Scott on March 2, 1961, and assigned to theassignee of the present invention. This form of recording paper is soldby the Heiland Division of the said assignee, and is identified as itspart number A-3 04796.

Other recording papers which may also be used to advantage in thepractice of this invention are those made and sold by Eastman KodakCompany and identified as its Kind 1591 and Kind 1592, and that made andsold by E. I.

, du Pont de Nemours & Company and identified as its 5000 A. to 20,000A. during any portion of the rapid latensification procedures hereindescribed produces no observable or significant effects. TheseWavelengths do not contribute to desensitization or latensification andwhen present, the wavelengths between 5000 A. and 7000 A. are usefulonly in viewing the record. Print-out papers which are desensitized by alow intensity light are found also to haxe an extreme reciprocityfailure at low intensities.

Using the latensifier method, as described above, in combination withrecording paper of the type described, it has been found that tracesappear well within a fraction of a second at paper speeds in excess of 8inches per second at any resolvable frequency, and an envelope atnon-resolvable frequencies.

While the latensifier lamp 13 has been illustrated as showing the coolwhite light tube 14 and the black light tube 15 as associated with thesame reflector, it will be apparent to those skilled in the art that, ifdesired, each of the fluorescent tubes 14 and 15 may be mounted inassociation with a separate and individual reflector, and arranged toprovide a desired spacing or separation thereof along the length ofrecording paper as it moves downwardly along the front face 4 of theoscillograph.

In the modified oscillograph latensifier arrangement illustrated in FIG.2, two latensifier lamps 16 and 17, each of which may be identical tothe lamp 13 shown in FIG. 1, and contains two black light tubes 15, arearranged sideby-side in front of the exposed longitudinal section of therecording paper 3 with the axes of the fluorescent tubes parallel to theplane of the recording paper 3 in that exposed region. As in thearrangement of FIG. 1, it is important that the direct rays of the lamps16 and 17 should not strike the paper nearer than about one inch belowthe amber window 12. In the region between the lower edge of the amberwindow 12 and the position at which these direct rays from the lamps 16and 17 strike the paper, the paper should be exposed to ambient orindirect light. In some cases, it may be desirable to supplement theradiation striking this intermediate region by cool white light such asprovided, for example, by the latensifier fluorescent tube 14 of FIG. 1.In other cases, ordinary incandescent lamps emitting a low intensity ofultraviolet light could be used for supplementing the ambient light. Atfaster paper transport speeds, the interval between the lower edge ofthe amber window 12 and the line or region at which rays from the lamps16 and 17 strike the paper may be increased to 2 or 3 inches.

FIG. 3 illustrates a modified latensifier arrangement according to thepresent invention in which the latensifying radiation is derived from alatensifier lamp 18 which desirably may include only fluorescent tubesproviding black light such as the fluorescent tube 15 shown in FIG. 1.As shown in FIG. 3, a graduated light filter or wedge 19 is provided atthe front 4 of the oscillograph immediately below the amber coloredwindow 12. The filter 19' is rectangular in shape and extends completelyacross the width of the recording paper 3 and for a suitable distancealong the length of the recording paper as the latter travels downwardlyalong the front face of the oscillograph. By way of example and notlimitation, it is contemplated that the width of this filter may be oneor two inches and so arranged that the intensity of radiation to whichthe paper is particularly sensitive passing through the filter andstriking the recording paper progressively increases as the paper movesdownwardly along the front of the oscillograph. With this arrangement,it is evident that the recording paper is exposed to a low intensitystate of radiation for the short time interval during which therecording paper is shielded by the filter 19, and is thereafter directlyexposed to the high intensity latensifying radiations emanating from thelatensifier lamp 18 as the paper passes out from under the filter 19 andon downwardly along the front of the oscillograph.

If desired, the latensifier lamp 18 in the modification of FIG. 3 mayinclude a cool white fluorescent tube corresponding to the tube 14 inFIG. 1 for supplementing the latensifying radiation to which therecording paper 3 is exposed.

While FIGURE 3 illustrates a method for providing progressivelyincreasing intensities of radiation utilizing only fluorescent tubesproviding black light such as the fluorescent tube 15 shown in FIG. 1,it will be apparent to those skilled in the art that, if desired, thesame effect can be produced without a filter and by substitutingbaffles, reflectors, or other known types of light attenuators for thefilter.

It will be apparent from the foregoing description that there has beenprovided, according to the present invention, a novel method foreffecting rapid trace latensification for providing extremely fastaccess to recorded information. This latensifying method is operativerapidly to produce an image or trace of phenomena occurring at eitherlow or high frequency, thereby making the image or trace quickly visibleand usable in full view and under control of the operator and giving tothe operator quick access to the recorded information in a period oftime significantly shorter than that obtainable by conventionalprocessing techniques. I

What is claimed is:

1. The method of recording the time-variations of phenomena underobservation comprising the steps of forming a beam of radiation,principally in the invisible portion of the spectrum, moving said beamof radiation along a path such that the beam position is representativeof the value of the phenomena under observation, focussing said beam ofradiation into a spot of high intensity on recording material coatedwith an emulsion primarily responsive to such radiations, moving saidrecording mate rial relatively to said beam of radiation and said spotto produce a latent image or trace of said spot on said recordingmaterial, and thereafter successively exposing said recording materialbearing said trace first for a short time to a low intensity state ofradiation having wavelengths to which said recording material isprimarily responsive, and thereafter to a high intensity latensifyingradiation defining substantially the same wavelengths, thereby toproduce rapid forced latensification of said trace without fogging.

2. The method of recording on, sensitized material recording coated withan emulsion responsive to radiation primarily in the blue andultra-violet portion of the spectrum, the time-variations of phenomenaunder observation comprising the steps of forming a beam of radiationdefining Wavelengths in substantially the same portion of the spectrum,moving said beam of radiation along a path such that the beam positionis representative of the value of the phenomena under observation,focussing said beam of radiation into a spot of high intensity on saidrecording material, moving said recording material relatively to saidspot of high intensity radiation to produce a latent image or trace ofsaid spot on said recording material, and thereafter successivelyexposing said recording material bearing said trace first for a shorttime to a low intensity state of radiation having wavelengths between3000 A. and 4000 A. in the range of the recording material sensitivity,and thereafter to a high intensity latensifying radiation definingsubstantially the last referred to wavelengths, thereby to produce rapidforced latensification of said trace without fogging.

3. The method of recording comprising the steps of forming a beam ofradiation including wavelengths between 3000 A. and 5000 A. into animage of high intensity on recording material coated with an emulsionprimarily responsive to such radiations to produce a latent trace ofsaid image on said recording material, and thereafter successivelyexposing said recording material bearing said trace first for a shorttime to a low intensity state of radiation including wavelengths between3000 A. and 4000 A., and thereafter to a high intensity latensifyingradiation in- 7 cluding wavelengths between 3000 A. and 4000 A., therebyto produce rapid forced latensification of said trace without fogging.

4. The method of recording comprising the steps of forming a beam ofradiation into an image of high intensity on recording material coatedwith an emulsion primarily responsive to such radiations to produce alatent trace of said image on said recording material, and thereaftersuccessively exposing said recording material hearing said trace firstfor a short time to a low intensity state of radiation havingwavelengths to which said recording material is primarily responsive,and thereafter to a high intensity latensifying radiation definingsubstantially the same wavelengths, thereby to produce rapid forcedlatensification of said trace without fogging.

5. The method of latensifying images which have been recorded onprint-out material comprising the steps of first exposing said materialbearing said images briefly to a low intensity state of radiationincluding Wavelengths in the range of initial recording sensitivity ofsaid material to desensitize the background of said material, andthereafter exposing said material to high intensity radiations definingsubstantially the same wavelengths to produce rapid forcedlatensification of said images without fogging.

6. The method of latensifying images which have been recorded onprint-out material comprising the steps of first exposing said materialbearing said images briefly to low intensity cool white light includingwavelengths in the range of initial recording sensitivity of saidmaterialto desensitize the background of said material, and thereafterexposing said material to high intensity black light definingsubstantially the same wavelengths to produce rapid forcedlatensification of said images Without fogging.

No references cited.

LEO SMILOW, Primary Examiner.

LEYLAND M. MARTIN, Examiner.

1. THE METHOD OF RECORDING THE TIME-VARIATIONS OF PHENOMENA UNDEROBSERVATION COMPRISING THE STEPS OF FORMING A BEAM OF RADIATION,PRINCIPALLY IN THE INVISIBLE PORTION OF THE SPECTRUM, MOVING SAID BEAMOF RADIATION ALONG A PATH SUCH THAT THE BEAM POSITION IS REPRESENTATIVEOF THE VALUE OF THE PHENOMENA UNDER OBSERVATION, FOCUSSING SAID BEAM OFRADIATION INTO A SPOT OF HIGH INTENSITY ON RECORDING MATERIAL COATEDWITH AN EMULSION PRIMARILY RESPONSIVE TO SUCH RADIATIONS, MOVING SAIDRECORDING MATERIAL RELATIVELY TO SAID BEAM OF RADIATION AND SAID SPOT TOPRODUCE A LATENT IMAGE OR TRACE OF SAID SPOT ON SAID RECORDING MATERIAL,AND THEREAFTER SUCCESSIVELY EXPOSING SAID RECORDING MATERIAL BEARINGSAID TRACE FIRST FOR A SHORT TIME TO A LOW INTENSITY STATE OF RADIATIONHAVING WAVELENGTHS TO WHICH SAID RECORDING MATERIAL IS PRIMARILYRESPONSIVE, AND THEREAFTER TO A HIGH INTENSITY LATENSIFYING RADIATIONDEFINING SUBSTANTIALLY THE SAME WAVELENGTHS, THEREBY TO PRODUCE RAPIDFORCED LATENSIFICATION OF SAID TRACE WITHOUT FOGGING.